FURIOUS South Sydney officials have lodged a complaint to Penrith after Sam Burgess was struck in the face by a spectator as he left the field at the completion of the Rabbitohs' 18-2 win over the Panthers on Friday.
A female supporter hit the England international forward just above the eye with a flag stick as he walked towards the change rooms.
Burgess didn't sustain any injury and was in good spirits as he left the stadium, but declined to comment on the incident.
However, Sam's mother Julie, who was watching the game that also involved her eldest son Luke and his younger sibling George, took to Twitter to vent her anger.
"Would love to meet the woman (I'm being kind) who hit Sam with a stick as he was leaving the pitch. Sorry Penrith people but that's not OK," she wrote.
Souths chief executive Shane Richardson made a formal complaint to the stadium manager and Panthers general football manager Phil Moss.
The NRL's integrity unit will almost certainly investigate the incident, which could lead to further scrutiny of security at Sportingbet Stadium.
Last year a pitch invasion marred the end of a Test match between Tonga and Samoa and the players left the field with two minutes remaining.
Players from both teams expressed concerns about safety following the invasion by overenthusiastic fans.
Panthers officials confirmed the club was made aware of the allegations on Saturday and said in a statement it would be investigating the matter.
The club said a female spectator had contacted the club regarding the incident and had agreed to co-operate fully with the investigation.